Cutting apparatus for paper and like webs

ABSTRACT

Paper and like material web cutting apparatus including a blade and a cutting knife rotatably mounted so as to enable the webs to be cut when engaged between the knife and the blade, the blade being mounted in such a manner as to be rockable to present a stationary edge during cutting and to enable the blade to be moved to an inoperative position when cutting action is not required.

United States Patent 91 Gahriels 1 Aug. 7, 1973 1 CUTTING APPARATUS FOR PAPER AND 3,136,194 6/1964 Greenhalgh 83/305 LIKE WEBS 3,149,516 9/1964 Caldwell et al..... 83/304 X 3,401,585 9/1968 Schmermund 83/341 [75] lnventor: Leonard Gabriels, Hollinwood, 3,522,751 8/1970 Waldura 83/304 England 3,552,251 1/1971 Neff et al 83/342 X [73] Assignee: Frastan (Hollinwood) Limited,

I Lancashire England Primary Examiner-Frank T. Yost 1. W Attorney-Salter & Michaelson [22] Flled: May4, 1971 [21] Appl. No.: 140,184 57 ABSTRACT Paper and like material web cutting apparatus includ- [52] US. Cl 83/305, 8 3/341, 83/349 ing a blade and a cutting knife rotatably mounted so as [51] Int. Cl 326d 1/38 to enable the webs to be cut when engaged between the 1 1 Field 01 Search 9, knife and the blade, the blade being mounted in such 342 a manner as to be rockable to present a stationary edge during cutting and to enable the blade to be moved to [56] References Cited an inoperative position when cutting action is not re- UNITED STATES PATENTS q 151,668 6/1874 Newman 83/305 1 Chim, 2 Drawing Figures 1,876,838 9/1932 Biggert, .Ir. 83/304 Patented Aug. 7, 1973 2 Sheets-Sheet l INVENTOR:

LEONARD GABRIELS ATTORNEYS Patented Aug. 7, 1973 2 Sheets-Sheet 2 FIELZ.

INVENTOR;

8 L N EMR O M o On kw O E JV CUTTING APPARATUS FOR PAPER AND LIKE WEBS This invention relates to cutting-apparatus for paper and like webs, of the type in which the web under treatment is engaged between the edges of a normally stationary transverse blade and of a knife fixed to a member which is rotatable about an axis parallel to such blade.

Apparatus of this type is commonly used in paper machinery, for example in machines for automatically measuring, cutting-off and rolling-up standardised lengths of wallpaper.

In some cases the knife is mounted upon a continuously rotating roller whose circumferential measurement determines the lengths of web cut off, and which therefore becomes unduly bulky when long sheets are required.

In other cases, the member carrying the knife is started and stopped through some form of intermittent mechanism, or has an eccentric gear drive whereby its rotational speed when cutting is different from its speed at other times, but each of these expedients tends to limit the maximum speed at which the web can be run, consistent with the cut sheets being accurate as to length.

The object of the present invention is to provide an improved cutting-apparatus which is not subject to any of the above-mentioned drawbacks, and in which the knife is held in its cutting position by cutting forces.

According to the invention, cutting-apparatus of the type referred to, and in which the knife is carried by a continuously-rotatable roller, is characterised in that the coacting blade is mounted upon a rockable corner whereby its cutting edge is stationary during cutting but is periodically movable to an inoperative position with reference to the knife roller.

In the accompanying drawings,

FIG. 1 is a fragmentary front elevation of one form of cutting-apparatus embodying the present invention; and

FIG. 2 is a section on the line 22 thereof.

In the example illustrated, the rotary shear knife 5 is mounted on a roller 6 which is incut at two spaced posi-, tions to provide a flat seating 7 for the knife 5, which is transversely slotted at 8 to receive screws 9 whereby it is clamped in position, and an intervening web of metal 10 carrying adjusting screws 11 which can be brought to bear upon the back edge of the knife 5 before the clamping screws 9 are tightened down. In this way, the operative edge of the knife 5 can be set accurately parallel to the axis of the roller 6.

It is known practice to fix the coacting stationary blade 12 to a rail or other corner 13 which is angularly adjustable about its longitudinal axis to a limited extent to ensure optimum cutting conditions, but according to the present invention the blade-carrier 13 is positively rocked about such axis in timed relation to the revolutions of the rotary knife 5 so that the blade 12 cooperates with the latter only at predetermined intervals.

Conveniently the blade-carrier 13 is a block equal in length to the knife-roller 6 and provided with end trunnions 14 for angular movement about a horizontal axis, the blade 12 being fixed in a rebate 15 in such block.

The trunnions 14 project through bearings 16 at opposite ends of a frame 17 in whose lower part the kniferoller 6 is journalled at 18 and arms 19 keyed to extremities of the trunnions are connected by links 20 to corresponding arms 21 on a rocker-shaft 22 which is operated (for example, by cam-and-follower mechanism) at a rate dependant upon that at which the kniferoller 6 is driven.

The links 20 are preferably formed as turmbuckles to allow adjustment of the angle through which the carrier block 13 is rocked to bring the blade 12 clear of the rotary knife 5 and at which it is held until the operation of the cam or other mechanism aforesaid allows the blade 12 to resume an operative position defined by abutment of the block 13 against an adjusting screw 23 in the head of the frame 17. The blade 12 is thus held firmly in its operative position by the cutting forces, without the aid of extraneous locking means or heavy springs, and a very light pressure on its actuating means will serve to displace it to an inoperative position, indicated in broken lines in FIG. 2.

When co-operating with one another, the edges of the rotary knife 5 and stationary blade 12 are not mutually parallel in a horizontal plane, but oppositely skewed with reference to the direction of travel of a web indicated at 24, and running between them so that such web will be cut with a true shearing action progressively across its width.

In order that such web shall be severed exactly at right angles to its length, the frame 17 is not fixed between the side members 25 of the associated machine, but has a fork 26 at one end which embraces a housing 27 on the adjacent member 25 and is pivoted thereto by means of aligned vertical pintles 28.

The other end of the frame 17 is slidably supported upon a bracket 29 projecting inwards from the second side member 25 and is adjustable through the medium of a hand-wheel 30, a pinion 31 fixed thereto, and a toothed rack 32 in the frame 17.

The knife-roller 6 is driven through a universal joint 33 having its coacting members journalled in the housing 27 for relative angular movement about a point on the common axis of the pintles 28, and when the frame I 17 has been correctly set it is secured by a clamping screw 34 passed through a slot 35 in its free end into the supporting brackets 29.

I claim:

1. Cutting apparatus for paper webs and the like comprising a shear knife blade mounted on a rotary roller, a coacting shear knife blade mounted on a pivotal frame, means operable in timed relation to rotation of said roller for pivoting said frame from a cutting position in which the blades coact to a noncutting position in which the blades are apart, said frame being in the form of a block having end trunnions for effecting the pivotal mounting thereof, said block having a rebate extending along one corner thereof in which said coacting shear knife blade is mounted whereby the cutting edge of the latter lies along said comer, said cutting edge being disposed behind the axis of said trunnions when viewed in the direction of gravel of said paper web whereby the cutting action of the apparatus automatically imparts a moment to said block tending to maintain same in its cutting position, stop means for limiting pivotal movement of said block at its cutting position, and lever means for positively pivoting said block to and away from said stop means to the cutting and non-cutting position, respectively.

I! 1 i t 1 

1. Cutting apparatus for paper webs and the like comprising a shear knife blade mounted on a rotary roller, a coacting shear knife blade mounted on a pivotal frame, means operable in timed relation to rotation of said roller for pivoting said frame from a cutting position in which the blades coact to a noncutting position in which the blades are apart, said frame being in the form of a block having end trunnions for effecting the pivotal mounting thereof, said block having a rebate extending along one corner thereof in which said coacting shear knife blade is mounted whereby the cutting edge of the latter lies along said corner, said cutting edge being disposed behind the axis of said trunnions when viewed in the direction of gravel of said paper web whereby the cutting action of the apparatus automatically imparts a moment to said block tending to maintain same in its cutting position, stop means for limiting pivotal movement of said block at its cutting position, and lever means for positively pivoting said block to and away from said stop means to the cutting and non-cutting position, respectively. 